Despite the public outcry over identity theft, the loss of personal information still appears to be on the rise.

Experts say the number of reported “breaches,” where sensitive personal data such as credit card numbers or financial information is lost or stolen, increased more than 40 percent last year.

“We think people are going to learn from their mistakes, but they aren’t,” said Mary Monahan, senior analyst at Javelin Strategy & Research, a Pleasanton research firm.

According to Monahan, 446 breaches were reported in the United States last year, exposing a total of 128 million records. In 2006, 312 breaches occurred, compromising 20 million records.

Last week, Agilent Technologies of Santa Clara added itself to the list of corporate victims. The maker of test and measurement equipment acknowledged that a laptop containing personal data on 51,000 current and former employees was stolen from a car of a vendor on March 1. The vendor, Stock & Options Solutions of San Jose, said it has since enhanced security measures.

“While we have no reason to believe that any of the information has been misused, we recognize that our clients entrust us with their data and have taken additional steps to ensure this sensitive information is as secure as possible,” Sean Lembree, chief executive of Stock & Options Solutions, said in a statement.

Fraud from the misuse of the information appears to be on the decline. In 2006, there were 8.4 million victims in the United States with losses of $51 billion, Monahan said. That fell to 8.1 million victims in 2007 with losses of $45 billion.

Corporations are making better use of technology to monitor their systems for possible fraud, she said.

Still, many companies haven’t yet put into place adequate policies to prevent the theft or loss in the first place. In some cases, they haven’t adopted technology that encrypts data on a laptop and makes it difficult for thieves to read.

Also, companies have not done a good job of educating their employees about privacy issues, said Paul Stephens, director of policy and advocacy at the Privacy Rights Clearinghouse, an advocate of consumer privacy rights. “You should not leave the building before the data is encrypted,” he said.

On security issues, smaller companies often lag behind larger ones, said Michael Weathers, senior vice president of governance and security at Fidelity National Information Services of Jacksonville, Fla., a data processing firm. Large businesses have invested significantly in their security systems, he said.

At Agilent, spokeswoman Amy Flores said no fraud has yet been linked to the missing employee data, which includes names, Social Security numbers and financial information. The company sent a letter to notify affected staffers, and the theft of the laptop is under police investigation.